From Conus grographus we have now isolated four peptide toxins which act by paralyzing vertebrate skeletal muscle. We shall continue work to establish the complete covalent structures of these molecules, and to examine their mode of action. Also present in the venom are several proteins which are toxic to mice when injected intracerebrally; the peptide toxins are ineffective by this route. We shall purify these toxic proteins so as to examine their modes of action individually. We shall continue work with other species of Conus. In particular the toxin(s) of Conus magus have already been obtained in partially purified form, and appear to be peptides of small to moderate size. Our aim is to obtain these in pure enough state to carry out structural work and to compare the mode of action with that of the toxins from conus geographus.